Texture of YBCO layer grown on GaN/c-sapphire substrates

YBCO thin films with epitaxial alignment were grown on (0001) oriented GaN/c-sapphire substrates using pulsed laser deposition. We performed a complete texture analysis and proposed a qualitative texture model explaining the measured X-ray pole figures of the YBCO films. The analysis revealed three texture components with the planes {00 1}, {113} and {207} parallel to the (0001) plane of the GaN surface. The six-fold symmetry of the GaN surface caused that all three texture components comprise six orientation variants. The orientation relationship of the variants with respect to the GaN/c-sapphire substrate was established. It was shown that thin MgO interlayer deposited on GaN/c-sapphire substrate before the growth of the YBCO layer can suppress the formation of the undesirable {113} and {207} texture components.

Automated summary

YBCO thin films were grown on (0001) oriented GaN/c-sapphire substrates with epitaxial alignment, and a qualitative texture model was proposed to explain the measured X-ray pole figures. The analysis revealed three texture components parallel to the (0001) plane of the GaN surface, with six orientation variants due to the six-fold symmetry of the GaN surface. It was shown that a thin MgO interlayer deposited on the GaN/c-sapphire substrate before YBCO growth could suppress the formation of undesirable texture components.